Electron discharge device



May 24, 1949. P. Kusel-1 2,470,856

` ELECTRON DISCHARGE DEVICE I Filed Aug.v 20, 1941 2 sheets-sheet 1 YMQMMW ATTORNEY P. KUSCH ELECTHON DISCHARGE DEVICE May 24, 1949.

2 Sheets-Sheet 2 Filed Aug. 20, 1941 INVENTOR Pwr/(HRP /faacw w27/@Mmm ATTORNEY Patented May 24, 1949 UNITED STATES PATENT OFFICE ELECTRON DISCI-IARGE DEVCE Application August 20, 1941, Serial No. 407,539`

(Cl. Z50-27.5)

12 Claims.

'I'he present invention relates, generally, to electron discharge devices, and has reference, in particular, to production of ultra high frequency oscillations.

Tuned. resonators have heretofore been employed, separated by a field-free space, and cooperating to first bunch the electrons and then catch them-at an advantageous moment when power may be derived therefrom. The usual construction of devices of this sort are affected with adverse space charge due largelyy to severe concentration of electrons in transit, and which inter alia, interferes with bunching at a sharply defined position.

The present invention seeks,` to remedy deficiencies in the prior art constructions, especiallyl those aforementioned, wherefore, it may be `said that an object of the present invention isto generally improve operation and efliciency of aresonant type electron discharge device.

A further object of the present invention is to, concentrate the electrons at a sharply defined hunched position, but in their transit to such position 4to keep them spread laterally from each other, and. accordingly, to reduce space charge effects.,

Anotherobject. of the present invention is to obtain a density modulation while maintaining constant velocity of. electrons.

Still further objectswill appear to those skilled inthe art asthe description progresses, 'both by direct statement thereof and by implication frcm the context.

In the accompanying drawing, whereinV like numerals of reference indicate similar parts throughout the several views;

Figure 1 is a side-edge view of an electron discharge device in accordance with my invention; and

Figure 2 is a sectional view thereof on line II`II;'

In-the specific embodiment of the invention illustrated in said drawing, two hollow-body resonators I 0, I I, of substantially doughnut or toroidal shape are shown, arranged so that the central planes of each are perpendicular to each other. For convenience in description and relative location, the rst ofthese resonators, ccmmonly known as the buncher, and here designated by numeral I0, will be considered as-standing upright4 on4 edge, whereas the other one, II, generally. designated the catcher, will. be considered asv resting atwise or horizontally. The centralgaxis ofdeveloped revolutionof the Afirst resonator or buncher I lies in the extended 2 central-plane ofthe second-resonator orucatcher. II, saidk axis and plane being. ndicatemby. the@ dot-dash line I2.. 'I'hemid-portions.oieachres-g onator provide attenuated walls as common .with1` this type of resonator. In the instance. of. the; catcher II, the attenuated ywallsconstitutepen forato-grids I3, I 4, the distance:-betweenwhicli is tunable in well known-manner. (notshovv/nl-l-` by changing the relative spacinggof. saidfgrids'f from each other. y

The two resonatorslil, I Il are showfnphyswcally separated one fromthe other-'and-jeinem by-a crescent-like conduit I-which en'ial'latesI from atop` part of the toroidal.. Wall"A of.- the buncher I- and merges with the catcher Hf around the upper grid I3. At the :juncture` ofi the buneher IU and ther crescent-likeA conduit#- trons. Said grid I'I is made positive'ftothecath-- ode, as by battery 22 and .suitable` connectionsi between gridand cathode, thereby -accelerating;y the-electrons upwardly and diametr-icall-y ofthe.v

resonator to pass into the crescent-like.conduit# I5. Resonance of buncher I, augmentedbya-n feed-back of oscillating energy from the secondresonator or catcher by interconnectedcouplingV loops 23, 24, produces an electriceld oscillat-r ingbetween the solid attenuated walls Zifofll thesaid buncher I0. This oscillation.affects-the-- electron beam, introducing asmall. lateral `componentof velocity tending to swing..the beani.A back-andforth1laterally, However,` since this#4r lateral component is exceedingly.- small# come' pared .to the forward velocity, it maybe said that the resultant forwardV velocity remains'sube` stantially the same.

Associatedwith the crescent-like conduitland resonators. is means for establishingand malt-1'@nu taininga constant magnetic field.V An electro magnet My isfshown for the purposerwithvitspolefpieces P, P at opposite sides ottheacresf" cent-like conduit for maintaining 'a constant field. The direction of that field is inward tward the paper in Fig. 2, or from left to right in Fig. l. Such a eld tends to cause electrons to adopt an arcuate path clockwise to the field direction. The intensity of the field is maintained constant both in terms of time and area of pole piece, thereby obtaining constant radius of curvature of the arcuate path described by an electron. The field intensity and shape of the crescent-like conduit are proportioned and arranged so that an electron not otherwise deiiected will describe a semi-circle through the middle of the crescent from end to end thereof from a midpoint A in the buncher l!! to a midpoint B in the catcher Il. It may now be said that any other electron having the same forward velocity and leaving point A will pass to point B, points A and B being situated on aforementioned plane l2. This is true of electrons to which a lateral component is given by field impulse of the buncher, whether that lateral component be from right or left. The lateral component, in effect, ininitesimally alters the radius of curvature and shifts the center of curvature up or down depending upon whether the lateral component is in a direction away from or toward the center of curvature. This has been illustrated in greatly exaggerated scale by showing normal path C of an electron A to B, as a true semi-circle of radius 1' about center of curvature p, and by showing paths D and E for extreme right and left deflected electrons respectively having substantially equal radii r and r" of path curvature centered at p' and P but describing paths less than and greater than semi-circular normal path C. However, since path D is shorter than normal path C, the time of travel of electrons through path D is less than for electrons traveling on normal path C, and similarly, since path E is longer than normal path C, time of travel of electrons through path E is greater than for electrons traveling on normal path C. Consequently, the modulation impressed by the lateral displacement or swinging of the electron beams at the buncher enables electrons in shorter path D to leave point A later than electrons on normal path C and both arrive at B at the same time, whereas electrons on path E which start sooner than those in normal path C arrive at B at the same time as electrons of the latter path C mentioned. The result, by use of appropriately tuned oscillation, magnetic field, voltage, coupling and other well known functional requirements in design, is a density bunching of electrons in the catcher at point E. Energy may be derived from these bunched electrons, a small portion being fed back by coupling 24 to coupling 23 and the major portion being fed to an output by a suitable coupling 2t in the buncher. The electrons pass through the lower grid of the catcher and expend their remaining energy within and against the walls of a collector 2l. It is to be understood that the collector, resonators, crescent-like conduit enclosure and envelope are inter-communicating with each other and are all evacuated.

In operation, it is to be understood that the foregoing description as to the three particular electron beams from the particular point A is duplicated by myriad other electrons passing through the buncher lll, so that the actual beam has a cross-sectional area substantially that of the upper grid I6 of the buncher. The periodic modulation applying a lateral component affects the whole cross-sectional area of the beam. In view of the enlarged cross-sectional area of the crescent-like conduit, and the deflection or different arcs of flow of the electrons, the said electrons are not crowded together in transit, the desirable consequence of which is substantial elimination of space charge effects and a very decided increase of efficiency over known electron discharge devices of the hollow-body resonator type. It must be remembered that the poles P and P of magnet M establish and maintain a Xed magnetic field, and that in such a eld an electron with a certain Velocity will describe an arcuate path of determinable radius which will always be the same under the given conditions. .Application of a lateral component of defiection does not introduce a substantial change of radius of curvature since the electron velocity has been only very slightly changed. Thus, only the center of curvature and the length of the arc without any material change of radius, are aiected by the introduced lateral component. The transit time accordingly is a function of the lateral displacement of the beam.

Electrons from the cathode are accelerated with potential difference Vc between cathode and grid. They pass between the attenuated midportion or plates 25 of the buncher IU across which a periodically varying eld potential difference Vd sin wi' exists, which thereby sways the electron beam back and forth with a periodically varying orientation of the tuned frequency of the resonators. The heretofore described bunching of electrons due to difference in transit time occurs in the catcher, and with hunched electrons passing through the field thereof when the field opposes the motion of the electrons, they will accordingly deliver energy to the field which causes the resonator to oscillate and accomplishes the desired output. The resonators are tuned to the oscillating frequency and the feedback from catcher to buncher is accordingly part of the coupling of the whole as a resonant system.

Since the various details of construction, as well as the precise relation and functioning of parts are subject to variation and change without departing from the inventive concept or scope of the invention, it is intended that all matter contained in the specification or illustrated in the drawing, shall be interpreted as exemplary and not in a limiting sense. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein shown and described and al1 statements of the scope of the invention herein set forth as a matter of language which might be said to fall therebetween.

I claim:

l. An electron discharge device comprising a buncher resonator and a catcher resonator at right angles to each other and having mid-points thereof in a common plane, means for producing a beam of electrons through the buncher resonator, electrode means for applying a lateral component of travel periodically on said beam, and means between said buncher and said catcher for establishing a curvature of fixed radius to the path of the electron beam, whereby a density modulation is produced effective at the catcher resonator.

2. An electron discharge device comprising a buncher resonator and a catcher resonator at right angles to each other and having mid-points thereof in a common plane, means for producing` aaneen-oi; eleotronefthronehrthebunohor rosee nator, feed-bac fronting catchenresonator to the buncher resonator for applying a lateral component off travel periodically onfsaid. beam in the .buncher resonatonandmoansbotweon.sadlounobor and ASeid catcher for establishing a curvaturek of. xed radius to the path of the electron beam, whereby a density modulation is produced effective at the catcher --resonaton electron discharge .deviceI comprising a buncher resonator and a catcher resonator atv rightangles to each other andhaving midapoints thereof-in .aeommon plane, means lfor producing a beam. of electrons through the buncher resonator, electrode means for applying a lateral component of travel periodically on said beam, and means between said buncher and said catcher providing a fixed magnetic eld transverse to the electron beam for establishing a curvature of xed radius to the path of the electron beam, whereby a density modulation is produced effective at the catcher resonator.

4. An electron discharge device comprising a buncher resonator and a catcher resonator at right angles to each other and having mid-points thereof in a common plane, means for producing a beam of electrons through the buncher resonator, feed-back means electrically connected from the .catcher resonator to the buncher resonator for applying a lateral component of travel periodically on said beam in the buncher resonator, and means between said buncher and said catcher providing a xed magnetic eld transverse to the electron beam for establishing a curvature oi xed radius to the path of the electron beam, whereby a density modulation is produced eiective at the catcher resonator.

5. An electron discharge device comprising a toroidal buncher resonator having attenuated solid walls at its middle portion, a toroidal catcher resonator having attenuated perforate grid walls at its middle portion, said resonators being angularly disposed with respect to each other, electrode means for producing a beam of electrons through the buncher resonator, means between said buncher and said catcher for applying a lateral component of travel periodically on said beam between the attenuated solid walls of the buncher resonator, and means for establishing a curvature of fixed radius to the path of the electron beam from the buncher resonator to the perforate grid middle portion of the catcher resonator whereby a density modulation is produced eiective at the catcher resonator.

6. An electron discharge device comprising a toroidal buncher resonator having attenuated solid walls at its middle portion, a toroidal catcher resonator having attenuated perforate grid walls at its middle portion, said resonators being angularly disposed with respect to each other, means between said buncher and said catcher for establishi-ng a curvature of fixed radius to the path of electron beam' from the buncher resonator to the perforate grid middle portion of the catcher resonator, and means for varying the length of arcuate path while retaining constant radius of arc of said electron beam, whereby a density modulation is produced effective at the catcher resonator.

7. An electron discharge device comprising a toroidal buncher resonator having attenuated solid side walls at its middle portion, a toroidal catcher resonator having attenuated perforate grid Walls at its middle portion, said resonators moans; eleotrioallr connectedand lying in a plane midway between and par lg., tc4 said; perforatesridfwalls thereof,4 endemo@ S for Projecting a modulated -oleotroaboamrom the. .machen-resonator to. lthe vrgrid',portion ,ofthe-.f catcher; resonator 8-Anfo1ootron discharge odevoofoomprisinaa-i toroidal buncher resonator l'iwaving`l attenua.. So1id..sido ,Walls at, its midollo portion, atorodl catcher f resonator havingV aitonuatedseorioraio f. grid. Walls. at its middle portion, saill-rosUmatilla,.` havinatransvelso relation ,one to thelothori. extended central axis through the buncher resonator perpendicular to said solid side walls crossing a similar axis of the catcher resonator and lying in a plane midway between and parallel to said perforate grid walls thereof, means for producing a beam of electrons through the buncher resonator between said attenuated side walls thereof, means for establishing a curvature of iixed radius to the path of electron beam from the buncher resonator to the grid middle portion of the catcher resonator, and means for varying the length of arcuate path of said beam, whereby a density modulation is produced effective at the catcher resonator.

9. An electron discharge device comprising a toroidal buncher resonator having attenuated solid side walls at its middle portion, a toroidal catcher resonator having attenuated perforate grid walls at its middle portion, said resonators having transverse relation one to the other, an extended central axis through the buncher resonator perpendicular to said solid side Walls crossing a similar axis of the catcher resonator and lying in a plane midway between and parallel to said perforate grid walls thereof, means for projecting a modulated electron beam from' the buncher resonator to the grid portion of the catcher resonator, and a crescent shaped conduit connecting said resonators for the modulated electron beam.

10. An electron discharge device comprising a toroidal buncher resonator having attenuated solid side walls at its middle portion, a toroidal catcher resonator having attenuated perforate grid walls at its middle portion, said resonators having transverse relation one to the other, an extended central axis through the buncher resonator perpendicular to said solid side walls vcrossing a similar axis of the catcher resonator and lying in a plane midway between and parallel to said perforate grid walls thereof, means for producing a beam of electrons through theA buncher resonator between said attenuated side walls thereof, a magnet of xed field between said resonators for establishing a curvature of fixed radius to the path of electron beam from the buncher resonator to the grid middle portion of the catcher resonator, and means for applying a lateral component of travel on said beam' for varying the length of arcuate path of said beam,

whereby a density modulation is produced effective at the catcher resonator.

11. An electron discharge device comprising a buncher resonator and a catcher resonator, electrode means for projecting a beam of electrons from the buncher resonator toward the catcher resonator, means between said buncher and said catcher for rendering the path traversed by said beam varying in length from the buncher resonator to the catcher resonator, and a conduit 7 progressively increasing in cross-sectional area from the buncher resonator to a distant portion therefrom for both admitting of the varying path lengths of the beam and to reduce space charge effects.

12. An electron discharge device comprising a buncher resonator and a catcher resonator, electrode means for projecting a beam of electrons from the buncher resonator on an arcuate path from the buncher resonator toward the catcher resonator, means between saidl buncher and said catcher for varying the arcuate length of path of said beam, and a crescent-like conduit connecting said resonators together `for said beam for both admitting the varying arcuate paths of i5 the beam and to reduce space charge effects by the electrons following such paths.

POLYKARP KUSCH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATESy PATENTS 

